| Description | Images | SH2-188The next planetary SH2-188 looks much like the Medusa Nebula though you'll see no blue in it. But the real clue that something different is going on here is that the "white" dwarf is not in the center of the arc as it is in the Medusa Nebula. The arc is very close to the star. It is the faint blue star near the rather obvious orange star well down and left of center. Near the center, there is a bright blue star but that is not related to the nebula. So how did the central star get so far off of center? The best idea to date is that this is a runaway star. At one time it was a member of a binary star system. That star, long long ago, blew itself up nearly completely. It didn't leave a neutron star or black hole. The companion star was then flung into space by its orbital velocity much as letting David's sling release its stone. Now this rather normal star was hurtling through space. When this star eventually turned into a white dwarf and lets its outer shell puff off the shell immediately ran into the interstellar gases. While both are less dense than the best vacuum we can create in our labs there was almost immediately a collision but a very lopsided one as the gasses from the opposite side of the shell were running away from the interstellar gasses so no collision could occur to any extent. The bubble was free to expand unbothered by the dust and gas between stars to the upper right but toward the lower left, the direction the star was moving at high speed, the collision immediately slowed down the shell given off by the central star preventing it from getting very far away from its source. This very violent collision makes the red arcs you see. Notice the brightest parts of the nebula are at the point of collision. The central star in this nebula is just too weak to cause the gases to glow blue so none is seen. Note the odd stuff in the lower left corner are due to bright blue and yellow stars just off the edge of the CCD and aren't real objects, just ghosts created when a bright star hits the very edge of the glass protecting the CCD. Some are available without the glass and don't have this problem but mine isn't available without a cover so this happens every now and then. If you want some deep reading on the nature of this object and how it was formed go to: |
| SH2-212Sh2-212 also has an NGC number, 1624 though this referrs to the open cluster not the nebula. The NGC catalog lists it as being 6 or 7 stars involved in nebulosity. Sharpless recorded the HII region that is the referred to as SH2-212. Actually, it is a far more interesting and studied object than you might expect. It is thought to be about 6 thousand parsecs away (about 20 thousand light years) and helps define the Perseus arm of our galaxy. This nebula recently helped decide a major issue of star formation. When a nebula forms new stars in its core it starts to be disrupted by the effects of these stars. The question was whether star formation could happen in the regions at the outskirts where this dust and gas was being blown or would the area be disrupted too much to allow stars to form before the region became too chaotic for this to happen. It turns out stars are being formed and some have just been formed in the outer parts of this nebula by the collect and collapse method. The stars we see in the center of the nebula formed some 4 million years ago. Those formed at the edge are still mostly hidden by the dust and gas that surrounds them and fed their creation. Related Designations for SH2-212SH2-212, NGC1624, NGC 1624, 2MASX J04403475+5027419, 87GB 043647.6+502152, 87GB[BWE91] 0436+5021, [WB92] 0436+5021, NVSS J044036+502744, 6C B043646.6+502153, 7C 0436+5022, SHARPLESS 212, [KC97] G155.4+02.6, |
| SH2-219SH 2-219 also known as LBN747 is a small emission nebula in western Auriga showing you it was imaged months ago and I'm just getting it processed. While there's been a lot of study on this compact emission nebula associated with a larger unseen molecular cloud, the distance to it is rather vague. The best estimate is about 13700 light years plus or minus 2000 light years. Using the 13700 figure it would be about 12 light-years across. It is thought to be very young, maybe no more than 100,000 years since the stars causing it to glow were born. Deep infrared shows a star cluster embedded in its southwest corner. That area is bluer than the rest so may have some reflection component from this cluster though I see no sign of its stars at visual frequencies. The IR POSS2 plate shows some hint of it. Also, there is reported to be a 2000 solar mass molecular cloud nearby but no other information about it that I could find other than it is about 24 light years long. This image is taken looking at the heart of the winter Milky Way. It's gas and dust seem to be blocking all but a very few distant galaxies. I couldn't find but a very few and only saw them after blowing up the image considerably. |
| SH2-226SH2-226 is one I apparently never did publish. It needs H alpha data to bring it out. I can't find much, if anything on it. It is also known as LBN 780. I can't find a distance other than a mention it is likely beyond the Auriga OB1 association which itself is in the outer reaches of our galaxy. Maybe it was the lack of info that caused me not to ever publish it. |
| SH2-228Sharpless 228 is also known as LBN 784. It contains a known infrared star cluster. Since I can't take images in infrared light it doesn't show in my shot. It is hidden by the dust of the nebula. What we do see in my shot is the ionized hydrogen on its surface caused to glow by super hot ultraviolet emitting stars that have escaped the confines of the nebula and are now causing the hydrogen on its surface to glow the characteristic pink color of ionized hydrogen. Sharpless 228 appears to be about 11,500 light-years away so is not a nearby object. An IR image of the cluster can be seen at: |
| SH2-235SH2-235 is considered to be caused by the collision of two vast molecular clouds. The collision has triggered a great amount of star formation that is only seen in deep dust-penetrating infrared light. I've seen it called the "Brain Nebula". It is about 1800 light-years away by some estimates. http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1996ApJ...463..630H&link_type=ARTICLE&db_key=AST&high= Related Designations for SH2-235SH2-235, |
| SH2-239Sharpless 239 is a mostly reflection/dark nebula with several Herbig-Haro objects embedded in it -- the pink spots. It also contains a mystery I've not been able to solve. Notice the three near star-like points in a triangle in its center. The POSS 1 and 2 plates show only two. The one at the lower left is missing! I've tried to find out about it but so far with no luck. My first thought was a variable star though I couldn't find any listed for its position. Checking what few images of this object exist on the net I find all modern ones show the star-like object but those dating to the time of the POSS plates don't. I contacted an astronomer in Hawaii that was supposed to be an expert and was told it was on his narrow band image (great shot with a 2.5 meter scope) but he provided no date. Since it wasn't a "new" object he wasn't interested and told me that it was worthless to compare narrow-band images to the POSS plates, totally ignoring the fact my shot wasn't narrow-band! I wrote him back asking why it wasn't allowed to compare wide-band red images to red POSS plates and got no reply. Maybe my email didn't get through his filters. My original email was relayed by another astronomer who I didn't bother to relay my reply. Thus he will remain nameless here. It appears that sometime between the POSS plates and today this object has come out of the murky depths of the nebula for us to see. Though in doing so it didn't change the nebula much that I can see. I do see a slight brightening in this area on the POSS 2 plates so it may have just started to appear about that time. Or maybe it is a variable star everyone since has caught at near maximum. I just don't know. |
| SH2-241Sh2-241 is an emission nebula in southern Auriga just below vdB65. I found several distance estimates. All put it over 15,000 light-years distant. The only one with error bars says 17,000 light-years +/- 3500 light-years. In any case, it is at least 4 times further away than its neighbor, vdB 65. Related Designations for SH2-241SH2-241, |
| SH2-242SH2-242 resembles, to my eye, a fish swimming to the left. The body is LBN 826 while the mouth, set off by a curving dark lane appears to be LBN 827. I'm no expert on these but it's the best I can determine. Most images of this object are done in narrowband which loses the reflection nebula around the probable illuminating star. It is a B0V star. It is located about 7200 light-years away in the northeast corner of Taurus. Thanks to the Tower of babble I imaged this under the LBN designations not realizing it was also on my to-do list as SH2-242. In fact, years later when I was putting this website together did my brain finally click. Fortunately, the SH2-242 designation hadn't yet been imaged so for once I didn't waste time retaking something. |
| SH2-247Sh2-247 in Gemini was imaged back in January. It was so faint my usual 2x10' color data was unusable. Even the luminosity frames were worthless but the 3 30 minute H alpha frames held usable but faint data. I need to try for color data using more and longer subframes but that will have to wait. For now, this will have to do. |
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